A big earthquake occurring in Mar. 11, 2011 notified threat of nuclear power in the whole world and global warming occurring by using fossil fuel is making major impact not only for human race but also for whole organism living on the earth. For human race, it now becomes urgent development of clean and safe earth-friendly renewable energy
As a representative energy recover method by heat engine, for example, it is raised thermal power generation and nuclear power generation. In these power generation, high temperature and pressure water vapor is produced by thermal power or nuclear power and turbine is rotated by water vapor, thereby electricity is generated. Although, in the above method, thermal energy is once converted to kinetic energy and work is done, thereby kinetic energy is recovered as electric energy, entropy is increased when internal energy is released from a physically restrained system and converted to kinetic energy, thus it is difficult to increase recovery efficiency of thermal energy by conventional technology. In normal thermal power generation or nuclear power generation, recovery efficiency is only to an extent of 30%-40% of thermal energy.
Further, as the other energy recovery methods, it is well known a method to generate electricity by recovering renewable energy. For example, it is conventionally known ocean thermal energy conversion and solar thermal power.
However, in these power generation methods, recovery efficiency of thermal energy is worse in comparison with thermal power generation or nuclear power generation and big energy loss occurs in supply of seawater of low temperature and low vapor pressure and both high heat source and low heat source and substantial recovery efficiency becomes fairly low. Therefore, it is hard to say that the above power generation methods can be replaced with thermal power generation or nuclear power generation. Further, there is also problem that electric-generating capacity is easily influenced by natural environment such as weather conditions.
Accordingly, the present inventor proposed in the past a system in which latent heat of vaporization of operating fluid is adsorbed from heat source with normal temperature, thermal energy is converted to kinetic energy during such process and efficiently recovered, the operating fluid after work is cooled down while being pressurized, thereby the thermal energy becomes to be easily released to the normal temperature, and according to the above method, liquefaction latent heat is released to the normal temperature and thereby cycles go around (see Patent Literature 1).
Further, according to the above system, the thermal energy can be stably recovered without being influenced by the natural environment such as, for example, wind-power generation or solar power generation and further power generation can be efficiently conducted by utilizing such thermal energy.